Mohd Najib Mohd Yasin
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Preferred name
Mohd Najib Mohd Yasin
Official Name
Mohd Najib , Mohd Yasin
Alternative Name
M. Yasin, M. Najib
Yasin, Mohd Najib
Yasin, Mohd Najib M.
Yasin, M. N.Mohd
Mohd Yasin, M. N.
Main Affiliation
Scopus Author ID
57210314287
Researcher ID
AAQ-6242-2021

Research Output

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Optimized Intelligent Classifier for Early Breast Cancer Detection Using Ultra-Wide Band Transceiver

2022-11-01 , Halim A.A.A. , Allan Melvin Andrew , Wan Azani Wan Mustafa , Mohd Najib Mohd Yasin , Muzammil Jusoh , Vijayasarveswari Veeraperumal , Abd Rahman M.A. , Zamin N. , Mary M.R. , Khatun S.

Breast cancer is the most common cancer diagnosed in women and the leading cause of cancer-related deaths among women worldwide. The death rate is high because of the lack of early signs. Due to the absence of a cure, immediate treatment is necessary to remove the cancerous cells and prolong life. For early breast cancer detection, it is crucial to propose a robust intelligent classifier with statistical feature analysis that considers parameter existence, size, and location. This paper proposes a novel Multi-Stage Feature Selection with Binary Particle Swarm Optimization (MSFS–BPSO) using Ultra-Wideband (UWB). A collection of 39,000 data samples from non-tumor and with tumor sizes ranging from 2 to 7 mm was created using realistic tissue-like dielectric materials. Subsequently, the tumor models were inserted into the heterogeneous breast phantom. The breast phantom with tumors was imaged and represented in both time and frequency domains using the UWB signal. Consequently, the dataset was fed into the MSFS–BPSO framework and started with feature normalization before it was reduced using feature dimension reduction. Then, the feature selection (based on time/frequency domain) using seven different classifiers selected the frequency domain compared to the time domain and continued to perform feature extraction. Feature selection using Analysis of Variance (ANOVA) is able to distinguish between class-correlated data. Finally, the optimum feature subset was selected using a Probabilistic Neural Network (PNN) classifier with the Binary Particle Swarm Optimization (BPSO) method. The research findings found that the MSFS–BPSO method has increased classification accuracy up to 96.3% and given good dependability even when employing an enormous data sample.

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Essential semiconductor films in micro-/nano-biosensors: Current scenarios

2021-10-01 , Subash Chandra Bose Gopinath , Ramanathan S. , Mohd Najib Mohd Yasin , Shapiai M.I. , Ismail Z.H. , Subramaniam S.

Background: Engineering nanoscale matter in a controlled functional system has expanded the area of science in the state-of-art of nanotechnology. The urgency in introducing real-time health monitoring sensors and rapid diagnostic tools in medical health is indeed high and crucial to date. The efforts are accompanied by nanotechnology to improve the sensors performances. In this line, semiconductor materials (Silicon/Silica) have been in well-focus to develop micro-/nano-sensors. Methods: Further, additional layering such as metal oxide and graphene material have elevated the current scenario in biosensor developments. Among these, two-dimensional graphene nanomaterial owns its remarkable mechanical, electronic, electrochemical, and optical properties, has excited the medical field to develop graphene-based biosensors for human health diagnosis and monitoring. The oxygen rich graphene materials enhance the bio-functionalization of recognition bio-elements for excellent graphene-based biosensor development. Significance: This review encloses the excellence of semiconductor materials in conjunction with biosensors for monitoring health and diagnosis. The advances and challenges encountered with developing semiconductors for nanobiosensors from laboratory set-up to the novel hand-held device for rapid and accurate human health care are outlined.

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Orbital Angular Momentum Vortex Waves Generation Using Textile Antenna Array for 5G Wearable Applications

2022-01-01 , Noor S.K. , Mawardi Ismail A. , Mohd Najib Mohd Yasin , Mohamed Nasrun Osman , Ramli N.

The development of wireless systems for fifth-generation technology (5G) has enabled the use of textile antennas for a wide range of applications, and it has now become one of the world's most in-demand technology. As the number of wireless devices and users increase, operators would need higher channel capacity to deliver better possible service to their customers. This paper presents the generation of Orbital Angular Momentum (OAM) vortex waves with mode 1 using a wearable textile antenna. OAM introduces a new scheme called Mode Domain Multiple Access (MDMA). OAM mode is an orthogonal mode with each mode carrying individual signals. Therefore, multiple signals can be sent using the same carrier frequency without additional resources. This allows the channel capacity and spectrum efficiency to be enhanced. The proposed antenna array comprises rectangular microstrip patch elements with an inset fed technique. Felt textile fabric was used as an antenna substrate. A carefully planned feeding phase shift network was used to excite the elements by supplying similar output energy at output ports with the required phase shift value. The generated OAM waves were confirmed by measuring the null in the boresight direction of their 2D radiation patterns as well as simulated phase distribution, intensity distribution and mode purity. The antenna covered portions of the 5G n77 band with a bandwidth of 81.7 MHz and an overall gain of 2.9 dBi. This is, to the best of our knowledge, the first work on generating OAM waves using a flexible textile material.

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Higher-order-mode triple band circularly polarized rectangular dielectric resonator antenna

2021-04-02 , Zambak M.F. , Mohd Najib Mohd Yasin , Ismahayati Adam , Iqbal J. , Osman M.N.

The paper presents a triband circular polarized rectangular dielectric resonator antenna. A single coaxial cable feeds the DRA to a double stub strip on the DRA side. A patch strip coupled to the feed assists in widening the bandwidth of the proposed DRA. The degenerate mode pair TEx∂11 and higher-TEx∂23 has been excited to achieve CP and enhance the antenna gain. The higher-order mode has been excited using a low-cost simple excitation mechanism without compromising on the size and shape of the DRA. An impedance bandwidth of 48% with a gain ~6–9 dBic was achieved in all resonance frequencies. Additionally, the AR bandwidth of 5.5%, 4.2%, and 2.76% was obtained at three different frequencies. Note that the proposed DRA exhibits a wide beamwidth of 112o, which is good for better signal reception. A comparison between the measured with simulated results shows that the measured results are matched by the simulated result trends.

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Size-Reduction of a Dual-Band Circularly Polarized Dielectric Resonator Antennas

2021-01-01 , Mohd Najib Mohd Yasin , Ali A. , Zambak M.F. , Radzi M.F.

In this paper, a circularly polarized rectangular DRA has been designed and simulated for WiMAX, satellite, 5G NR band applications. The design uses an F-shaped conducting patch with a parasitic patch to excite the design. The bandwidth enhancement of the design has been achieved thorough the optimization of the patch placement and gap distance for both conducting patch and parasitic patch to cover the desired operating frequency. The S11<10 dB and axial ratio< -3 dB result covers the operating frequency range. The designing and optimization of the design has been carried out using the CST Studio Suite software.

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Development of cascaded voltage doubler rectifier for RF energy harvesting

2022-02-21 , Ismahayati Adam , Mohd Najib Mohd Yasin , Ibrahim S.Z. , Haris N.

Radio Frequency (RF) energy harvesting is a process where RF energy from the ambient source is collected and converted into an electrical energy by using a rectifier circuit. However, the collected RF energy only supplies very low input power. Therefore, it is important to design a circuit that not only rectified the RF signal, but also with amplified characteristic to obtain a higher output voltage from a low input power. Driven by the increasing use of Internet of Things (IoT) devices operating in the 2.4 GHz Industrial, Scientific, and Medical (ISM) band, the presented rectifier circuit in this paper is designed in the same band as well. Initially, the voltage doubler circuit is chosen as the primary rectifier circuit, afterward cascaded into several stages until the most optimized result is obtained. The optimization is investigated across-30 dBm to 0 dBm of RF input power by varying the value of capacitor and resistor at a single stage. Based on the topology analysis, Dickson topology yields slightly higher voltage compared to Villard. In turn, the optimized number of stages is 6 because higher stages resulted to less output power. The measured reflection coefficient of the fabricated prototype is better than 40 dB at the center frequency with 240 MHz bandwidth. The rectified voltage is 3.4 V with 0 dBm input power. When it is supplied by 5 dBm input power, the green LED that connected to rectifier circuit output is light-up, confirming the RF energy harvesting application.

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A Review of Circularly Polarized Dielectric Resonator Antennas: Recent Developments and Applications

2022-12-01 , Abd Rahman N.A. , Mohd Najib Mohd Yasin , Ibrahim I.M. , Muzammil Jusoh , Noor S.K. , Ekscalin Emalda Mary M.R. , Zamin N. , Nurhayati N.

A comprehensive review on recent developments and applications of circularly polarized (CP) dielectric resonator antennas (DRAs) is proposed in this paper. DRAs have received more considerations in various applications due to their advantages such as wide bandwidth, high gain, high efficiency, low losses, and low profile. A broad justification for circular polarization and DRAs is stated at the beginning of the review. Various techniques such as single feed, dual, or multiple feeds used by different researchers for generating circular polarization in DRAs are briefly studied in this paper. Multiple-input-multiple-output (MIMO) CP DRAs, which can increase channel capacity, link reliability, and data rate, have also been analyzed. Additionally, innovative design solutions for broadening the circular polarization bandwidth and reducing mutual coupling are studied. Several applications of DRA are also discussed comprehensively. This paper finishes with concluding remarks.

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Characteristics of multiwavelength fiber laser employing semiconductor optical amplifier in nonlinear optical loop mirror with different length polarization maintaining fiber

2020-01-08 , Husshini N.F.H. , Nor Azura Malini Ahmad Hambali , Mohamad Halim Abd. Wahid , Shahimin M. , Mohd Najib Mohd Yasin , Norshamsuri Ali @ Hasim , Al-Asadi H.A.A.

In this paper, we propose and demonstrate generated characteristics of a multiwavelength fiber laser based on semiconductor optical amplifier in a nonlinear optical loop mirror with different length of polarization maintaining fiber. The configuration comprises 3-dB optical coupler, semiconductor optical amplifier and, 2 meters and 10 meters of polarization maintaining fiber. Characteristics of multiwavelength fiber laser are studied through the use of polarization maintaining fiber at different lengths. The experimental results revealed the number of lasing lines increases with the increment of the polarization maintaining fiber length. The polarization maintaining fiber with 10 meters of length has the ability to generate a higher number of lasing lines up to 47 signals with semiconductor optical amplifier injected current at 180mA, respectively. However, in terms of average peak power and average optical signal to noise ratio, the 2 meter of polarization maintaining fiber length has the capability to produce a higher value which is 0.45mW at 250mA of semiconductor optical amplifier driven current and 28.86dB at 170mA of semiconductor optical amplifier driven current, respectively. Furthermore, it is observable that this configuration capable to generate a wider bandwidth which is operating in the conventional (C) band to long (L) band at the room temperature.

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A Low-Profile Dielectric Resonator Antenna Array for OAM Waves Generation at 5G NR Bands

2023-04-01 , Abd Rahman N.A. , Noor S.K. , Ibrahim I.M. , Mohd Najib Mohd Yasin , Ismail A.M. , Osman M.N. , Ismail S.B.

This paper presents the generation of orbital angular momentum (OAM) vortex waves with mode +1 using dielectric resonator antenna (DRA) array. The proposed antenna was designed and fabricated using FR-4 substrate to generate OAM mode +1 at 3.56 GHz (5G new radio band). The proposed antenna consists of 2 × 2 rectangular DRA array, a feeding network, and four cross slots etched on the ground plane. The proposed antenna succeeded in generating OAM waves; this was confirmed by the measured radiation pattern (2D polar form), simulated phase distribution, and intensity distribution. Moreover, mode purity analysis was carried out to verify the generation of OAM mode +1, and the purity obtained was 53.87%. The antenna operates from 3.2 to 3.66 GHz with a maximum gain of 7.3 dBi. Compared with previous designs, this proposed antenna is low-profile and easy to fabricate. In addition, the proposed antenna has a compact structure, wide bandwidth, high gain, and low losses, thus meeting the requirements of 5G NR applications.

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Analysis of Symmetric Two and Four-coil Magnetic Resonant Coupling Wireless Power Transfer

2022-04-01 , Ali A. , Mohd Najib Mohd Yasin , Rambe A.H. , Ismahayati Adam , Ramli N. , Hasliza A Rahim @ Samsuddin , Thennarasan Sabapathy , Mohd Natashah Norizan , Sobri S.A.

This study examined the efficiency of power transfer for two-coil and four-coil spiral magnetic resonant coupling wireless power transfer (WPT) using distance to coil diameter (D/dm) ratio and reflection coefficient, S21 value. Adding resonators reduced the total resistance in the two-coil WPT system while increasing the S21 values of the whole system. A same-size spiral coil was proposed for the system and simulated using computer simulation technology (CST). A prototype with similar specifications for a four-coil design was implemented for verification. The proposed method yielded an optimal efficiency of 76.3% in the four-coil system, while the two-coil WPT yielded a 23.2% efficiency with a 1.33 D/dm ratio.

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